A conventional bulb assembly is designed for firmly engaging the bulb holder with the socket, as shown in FIGS. 1 and 2. An extended rod (11) is formed on the holder (1) downward and a gap (21) is formed at bottom side of the socket (2). The rod (11) has an engaging end (111), which can engage with the gap (21) when the holder (1) inserts into the socket (2) to obtain a secure connection. When the bulb of this conventional bulb assembly is broken and must be replaced, referring to FIGS. 3 to 5, user must press the lower end of the extended rod (11) by his one hand and uses the other hand to pull out the holder (1) and the bulb. It is very inconvenient and difficult.